Trailer brake



. Sept; 3,. 1946;

J. T. HORNE 2,407,156

' TRAILER BRAKE Filed Aug. 17, 1944 '2 Sheets-Sheet 1 p 4 H, HORNE v2,407 156 TRAILER BRAKE File d Aug. 17, 1944 2 Sheets-Sheet 2 InventorPatented Sept. 3, 1946 UNITED STATES PAT; ENT QFFIC s TRAILER BRAKE 2John TheoHorne, Layton Utali ApplicationrAug-ust- 17, 1944, SerialNor549,869' lqGlaimv, (Cl. 188142.)

1; v Thisinvention'relatestocabrakefontrailersand like and moreparticularly to an: actuatingide'vice for-such":a brakingsystem,

A primary object'of this invention is the-pros vision of an improvedmechanism actuatedhbyrthe momentum of a-trailer orsimilarvehicle-fonxapplying the brakes toa trailerswhenritheaforward speed of thetowing vehicle is' -decreased;

An additional important object is-the provision of means whereby'thebrake actuating-mechanism may be rendered temporarilyinoperativacaspfor.

example, when backing thetrailenbyth'stowing,

vehicle. t further objeot is -the provisior-rwf means wherebythebrake=pressure may be readil y:.'ad justed in the system; I

A still further object is -tl'i'e provision f: a h y= draulic" brake''actuati-ng devicewhich r wii'l ibe sturdy and-durable inconstruction,reliable and efiicient' in operation, and relatively simpl andinexpensive -to 'install and manufacture.

Other objectswill in part'be obvious andinpart he -pointed outhereinafter and disclosed 'in: the accompanying'drawi-ngs 'whereinthere: is shown a' prefrredform of this inventive conceptt"In'thedrawings:

Figure 1 is a perspective" view showing the brake actuating mechanism ofthis-invention"- as applied to a=trai1rand a towirrg vehicle.

Figured is a sectionalwiew-takenlongitudinally through the: center ofthe device shown imFig-ure 1.

Figure 3' is -a=perspective view of certain' constructional detail-sshown in conjunction with the wiring diagram fdr operation thereof, and

Figure l 4-is an enlarged fragmentary sectional view of certainoperating parts disclosed in-Figure 2 showing the same in adifierentposition-chad justment.

Like reference numerals refer to like parts throughout the several viewsof the drawings.

Having reference now to the drawings, the brake actuating device of theinstant invention generally indicated at 55 is comprised of a casing Ithaving a depending lug 52 with bolt holes !3 tlierethrough to which. areadapted tobe secured the towing arms is of a trailer of any desired type(not shown). One end of a draw-bar I5 extends outwardly from casing l land is adapted to be secured in. any desired conventional manner to atowing vehicle. Such connection may take the form of a ball and sockettype joint I6 secured to a clamp I1 adapted to be fitted to the bumperl8 of any desired type of towing vehicle (not shown).

As best shown in Figure 2 a recess threaded'porti'ontlofdraw--bar..;l*5: Thus'itrwill 20 'is cut .into casingd I "closed byaEGIOS'lII-I'G plate 2 I- secured thereto bygheavy screws 22 engagedinsuitable threadedftapertures in"; the end-wall; of easing I i: Plate "2|:hasazcentrallydisposedapers tures 23* therethrough; through whichextends draw-bar :I 5. A suitable 1 dust: shield 124 or rubber or"similarlflexiblermaterialis securedabout draw bar I5jasuby a retainingring;-25:and heldrto cover plate if I 1 as; by means. of; screws 237ito; preclude the ingress of dust OIXTO'DhEIYi foreign-matter "130717116interior:ofitheimechanismn L Positioned; about drawr-ban I 5vwithin:recessjl) is la heavy; duty :compressi-on shock i spring; 21 -one end ofwhichiabuts-theinner face Lofc1osure=mem.; her-:21 the other;endloii'springafi II is seated against a :Washer 28.; of 'steel: orthe:;like1 positioned-"won draw+bar I 5" and held in; .positiomby; apair;- of lockinglsnuts129*andai'30rmounted on-ma suitably be seen thatby :varying th positions of 1311135329 and thewcompression of:theaspri-ng '21 maybe varied as desired; Thezsmingrfldsmtthe-compression type .andiis normallyiinactive androffers no 4 pressureon .the: draw-:bar :I 5eto compress; the fluid by thepistonsfil";and:33r'when-:the vehicle is stationary on level ground;Spring: 21 -is-ralso heavy: enough? with: comparison" to spring 52;sothat: adjustment of "L the-tension :of spring"; 5 2 will have noappreciable effect on: spring" 21 orz'on draw-bar l 5' when the brakeis:inneutral position: Positioned on the opposite :side a-of": nut 30wisrasecond steel :collar 32 zand va rubber :ShOCk washer adaptedi to preventpossible stripping: of threaded. portion-Q31 if," for; any reason: thelay: draulic system (to be describedi'hereinafter). should becomeinoperative; and drawbanrl 5 be forced inwardly until'the washer:strikesxth'e: bOte tom ofcrecess 529; I The-draw-rbar: I E zextends:into a bore 35 "and te'rininates in 11a .zreducedtportion'iii upon whichare positioned and secured two spaced plunger leathers 31 and 38, thepurpose of which will be described hereinafter.

A reservoir 41] for hydraulic fluid is secured as by bolts 4| to the topof casing II and provided with an inlet 42. A flange 43 is formed on theinterior wall'of the reservoir about inlet 42 in order to prevent thecomplete filling of the easing with hydraulic fluid in order toaccommodate fluid from the hydraulic system when the pressure therein isreleased in a manner to be described hereinafter. Inlet 42 is interiorlythreaded and is adapted to be closed as by a threaded plug 44. Intakeand bY-pass ports 45 and 46 are cut through the wall of casing IIbetween reservoir 49 and bore 35, and an outlet port 41 leads from bore35 to a tube 48 leading to any desired type of hydraulic brakingmechanism associated with the wheels of the trailer.

The end of bore 35 is internally threaded for a substantial distancetherealong and has positioned therein an adjusting nut 49. A closure nut50 passes through a gasket and serves effectively to seal the end of thebore. A spring 52 is positioned within bore between the inner end ofadjusting nut 49 and plunger leather 38. It will now be seen that as thespeed of the towing vehicle is reduced, continued forward travel of thetrailer at the same speed causes an inward telescopic movement of thedraw-bar I5 and a corresponding movement of the plunger at its extremity36 and that such plunger acting on the fluid in the brake systemcompresses the same to act in a known manner to apply the brakes of thetrailer. When the trailer has been slowed to a degree commensurate withthe speed of the towing vehicle it will be readily apparent that theload is again taken up by the draw-bar l5 and cushioned by spring 21. Itwill also be seen that the compression of sensitivity spring 52 may bereadily adjusted by rotation of adjusting nut 49 lease the pressure inthe hydraulic system under such conditions at the will of the operator.Such means take the form of a valve 55 comprised of a turning plughaving a slot 56 therethrough mounted for rotation in a port 51 betweenreservoir and bore 35 and positioned at a point beyond the maximum pathof travel of the plunger. Obviously, when the valve is turned to openposition, that is, with aperture 56 aligned with port 51, compression ofthe fluid within the brake system by plunger 38 is impossible as fluidis permitted to escape through the port back into the reservoir 40which, as previously pointed out, is nevercompletely full in order toallow for such escape of fluid from the system when necessary. One endof the turning plug extends outwardly through the side wall of casing Il and has secured thereto a lever 58 to which is secured, pivotally, oneend'of a rod 59, the other end of which is pivoted as by a pivot pin 60to the plunger 6! of a conventional solenoid contained in a casing 62secured to the side wall of casing H, a suitable flexible dust shield 63being providedto preclude the ingress of foreign matter to the workingparts of the solenoid. As indicated in Figure 3, suitable hot and coldlines 64 and 65 lead from a battery 66 to opposite terminals ofthesolenoid 62 and the flow of current is controlled by a switch 61located in a position to be readily accessible to the driver of thevehicle. In practice it is preferred that lines 64 and 65 be containedin a suitable conduit 58. In Figure 3, switch 61 is shown in openposition and correspondingly valve 55 is shown in closed position. Whenit is desired to open valve 55 switch 61 is closed and acts through thesolenoid and its associated plunger 6| to move rod 59 and hence link 58to rotate valve 55 to the position shown in Figure 4. When it is desiredto return the trailer brakes to service, switch 61 is opened and thecurrent energizing the solenoid accordingly cut-ofi whereupon the valve55 is returned to closed position in any desired manner as by acompression spring within casing 62 acting on plunger 6| Now from theforegoing it will be seen that there is herein provided a trailer brakeactuating mechanism which accomplishes all the objects of this inventionand others including many advantages of great practical utility andcommercial importance.

As many embodiments may be made of this inventive concept and as manymodifications may be made in the embodiment hereinbefore described andshown in the accompanying drawings, it is to be understood that allmatter herein is to be interpreted merely as illustrative and not in alimiting sense.

I claim:

A combined trailer hitch and brake actuating mechanism which includes acasing adapted to be attached to the towing arms of a trailer vehicle,said casing having an axial bore opening adjacent one end into anenlarged chamber, a plug closing the end of the bore opposite thatopening into the chamber to form a fluid tight joint, a draw bar, oneend of the draw bar being adapted to be attached to a towing vehicle,the opposite end of said draw bar telescopically entering the bore inthe casing, means yieldingly connecting the draw bar to the casing, sothat when pull is exerted on the draw bar the casing will be moved,non-compressible fluid Within the bore between the end of the draw barand the plug, a pipe connecting the bore in the casing with the brakingsystem on a trailer vehicle whereby when the draw bar telescopes intothe bore the fluid contained therein will be forced into the brakingsystem on the trailer vehicle to set the brakes thereon and manuallycontrolled means to by-pass the fluid and avoid building pressure in thetrailer vehicle braking system when the trailer is being backed by thetowing vehicle.

JOHN 'I'I-IEO HORNE.

